Loud-speaker



y 1929. .c. L. FARRAND ETAL 1,712,759

LOUD SPEAKER Filed Nov. 5, 1926' 2 Sheets-Sheet 1 Q VENTORJ X z BY ff %,Z2%Z

ATTORNEYS y 14, 1929- c. L. FARRAND ET AL 1,712,759

LOUD SPEAKER Filed Nov. 5, 1926 2 Sheets-Sheet 2 5% i l ENTORS WWW? (Z; zazwwi ATTORNEYS Patented May 14, 1929.

onrrso srares PATENT @FFlfiE.

CLAIR 'L. FABBAND, OF FOREST ZHILL$, NEW YORK, AND ERNEST BOSS, 013 EAST ORANGE, AND PAUL F. GQDLEY, F UPPER MONTOLAIR, NEW JERSEY; SAID GOD- .LEY AND SAID'ROSS ASSIGNORS '10 FARR/AND MFG. CO. INC., OF LONG ISLAND CITY, NEW YORK, A CORPORATION GE NEW JERSEY.

LUUD-SPEAKER.

Application filed November This invention relates to loud speakers and particularly to loud speakers of the cone type. A well-known type of loud speaker has a diaphragm structure which comprises a cone and a cone frustum positioned with their bases toward each other and cemented together at their outer edges. Loud speakers of this kind are known as double cone speakers. One of the problems presented. in '10 the manufacture of double cone speakers 1s to produce an eflicient and neat joint betweenthe cone and the cone irustum. In the commercial manufacture of loud speakers this joint should be of such a character that it can be readily and quickly produced with-i out sacrificing the efficiency and neatnessof the joint. It is one object of this invention to provide an improved joint between the cone and the cone frustum in a loud speaker 0 of the double cone t pe which may be quick ly and readily pro uced in the commercial manufacture of the loud speaker and which,

will be eflicient and neat in appearance. It

is a further object of the invention to provide an improved joint between the edge oi any diaphragm and a supporting member or the like located at the back of the diaphragm,

regardless of the exact construction of the diaphragm and regardless of the exactly construction of said member.

The accompanyin drawings illustrates the invention as applie to aloud speaker of the so-called double cone type, but as hereinafter pointed out the improved joint may be utilized in a loud s eaker whose construction is quite different om that disclosed in the drawings.

In the drawings:

Fig. 1 is a front elevation of a loud speaker embodying the invention;

Fig. 2 1s a side elevation of the speaker shown in Fig. 1; and i Fig. 3 is an enlarged vertical section through the joint between the cone and the cone irustum.

The loud speaker shown in the drawings comprises a conicaldiaphragm 1 and a cone frustum 2 both made of fibrous material ch as paper. The cone and cone irustum :2 are positioned with their bases toward each other 5, 1926. Serial No. 146,34'8.

and are joined together by the particular type of joint forming the subject matter of the present invention.

The remaining structure of the loud speaker itself is not important so far as an understanding of the present invention is concerned, but it might be stated briefly that the remaining parts comprise a ring structure 3 in which the edge of the cone frustum 2 1s clamped, a base 4 and supporting rods 5 for supporting the ring structure on the base. These rods are secifred to the ring structure at 6 and are housed within the cone structure. They pass downwardly through an opening 7 in the lowermost portion of the cone structure and are secured to the base at their lowermost ends. The rods 5 also serve to support the electromagnetic actuating mechanism 8 havin an actuating rod 9 connected to the apex oi the cone 1 to vibrate it in the well known manner.

The improved joint between the cone 1 andthe conefrustum 2 is formed as follows: The cone 1 is provided with a peripheral portion 10 which is bent or flared outwardly and the cone irustum 2 is provided with 8. corresponding peripheral portion 11 which is bent or flared in the opposite direction. When the. cone 1 and cone frustum 2 are positioned with their bases toward each other the outward ly bent portions 10 and 11 form between them a p ripheral groove or recess. Within this recess is positioned an ornamental cord 12 which is held in place by a fillet of adhesive which also serves to cement the cone to the cone irustum. The best results have been obtained in practice by bendin the portions 10 and 11 to such an extent that they form between them an angle of approximately 90. "in the commercial production of loud speakers of the type described above the cone irustum 2, either with or without the ring structure secured to it, and the cone 1 are held'in two parts of a suitable machine which are made to approach each other until the edges of the cone and cone frustum meet. The parts of the machine are then rotated to cause the cone and cone frustum to make one complete rotation in unison. During this rotation a stream of adhesive is fed to the iii groove or recess between the peripheral portions 10 and 11. The cord 12 is also apphed to the recess during the rotation of the cone and cone frustum by positioning one end of the cord in .the recess where it will be gripped by the adhesive and then causing the cord to wind into the groove as the diaphragm structure rotates. The entire structure 1s then allowed to stand until the adhesive sets and binds the parts together, or if desired, heat may be applied to the joint to. set the adhesive more quickly.

The fillet of adhesive 13 not only serves to secure the cone 1 to the cone frustum 2, but it also serves to cement the cord 12 in place. In fact all three parts, namely the cone, the cone trust-um and the cord are all bonded together into a unit by the fillet of adhesive so that the cord really plays an important part in attaching the cone to the cone frustum. I

The cord 12 conceals the joint between the cone and the cone frustum and greatly 1mproves the appearance of the loud speaker, especially when the cord itself has an attractive appearance. The groove or recess be tween the peripheral portions 10 and 11 not only serves as a trough for the adhesive but also serves as a peripheral seat for the cord.

The type of joint described above is applicable to many differentkinds of loud speakers regardless of whether the diaphragm 1 1s conical in shape or flat, and regardless of whether the member 2 is a frustum of a cone, a complete cone or any other member located at the rear of the diaphragm. For instance, it might be a sheet metal supporting member such as used insome types of radio loud speakers. Furthermore, the cord 12 need not be an actual cord in the restricted sense of this term, but might be any filler which performs the same function as the cord. Moreover, the cone 1 need not be made of fibrous material as this part of the diaphragm structure, as well as the rear member 2, may be made of any suitable material which will permit the two parts to be joined together by a joint of the type herein disclosed.

The cord not only gives a finished and pleasing appearance to the loud speaker, but also fiplays an important part mechanically in e ecting an etlicient and permanent joint between the two parts of the diaphragm structure. The use of a joint of the type herein described greatly simplifies and cheapens the assembly of the diaphragm structure in the commercial manufacture of the loud speakers, because it is only necessary to rotate the two parts of the cone in unison, feed adhesive to the peripheral groove and at the same time allow the cord to wind into the groove. The application of the cord to the groove may be readily accomplished by hand. by placing one end of the cord in the groove where it will be held by the adhesive and then directing the cord in the groove as the two parts of the cone rotate, and as the cord tends to wind around the diaphragm structure, sufficient tension being applied to the cord to seat it firmly in the groove.

We claim:

1. A loud speaker comprising a conical diaphragm, a supporting member engagingv the diaphragm around its peripheral portion, and a cord encircling the periphery of the structure and located at the junction between the conical diaphragm and said supporting member, the supporting member and. the conical diaphragm being cemented together at Slid junction and being cemented to said cor 2. A loud speaker comprising aconical diaphragm, a supporting member for the dia phram having a periphery corresponding in shape with the periphery of the diaphragm, the peripheral portion of the conical diaphragm forming a recess with the peripheral portion of said supporting member, and a cord seated in said recess.

3. A loud speaker comprising a conical diaphragm, a supporting member for the diaphragm having a periphery corresponding 1n shape with the periphery of the diaphragm, the eripheral portion of the conical diaphragm orming a recess with the peripheral portion of said supporting member, a cord seated in said recess and a fillet of adhesive binding the cord, the supporting member and the conical diaphragm together.

l. A loud speaker. comprising a conical diaphragm, a supporting member cemented to the diaphragm around its peripheral portion, and a cord encircling the periphery of the structure and cemented to said su porting member and to the diaphragm, said cord concealing the joint between the supporting member and the diaphragm.

5. A loud speaker comprising a diaphragm structure including two members each of which is at least a portion of a cone, said members being positioned with their bases together and being cemented together near their edges, and a cord encircling the periphery of the structure and cemented to said members, said cord concealing the joint betweerg the two members.

6. loud speaker com risin adia hragm structure including twd mel bers such of which is at least a portion of a cone, said members being positioned with their bases together and the peripheral portion of one of said members forming a recess with the peripheral portion of the other member, a cord located in said recess and a. fillet of adhesive binding together the cord and said members.

7. A loud speaker comprising a conical diaphragm and a cone frustum positioned with their bases together, the edge portions of the diaphragm and cone frustum flaring outwardly to form a peripheral recess between them, a cord in said recess and a fillet of adhesive binding together said cord, diaphragm and said cone frustum.

8. A loud speaker in accordance with claim 7 in which the diaphragm and cone frust-um are made of fibrous material.

9. A loud speaker comprising a diaphragm structure including two fibrous members each of which is at least a portion of a cone, said members being positioned with their bases together and being joined near their edges and each member having a peripheral portion flaring outwardly to form a recess between them, and a cord located in. said recess and encircling the periphery of the diaphragm structure.

10. A loud speaker comprising a dia phragm structure including two members each of which is at least a portion of a cone, said members being positioned with their bases together and being joined near their edges and each member having a peripheral portion flaring outwardl to form a recess between them, and a, filer located in said recess concealing the joint between said members 11. A. loud speaker comprising a diaphragm structure including two members each of which is at least a portion of a cone, said members being positioned with their bases together and having outwardly flaring peripheral portions forming a recess between them, a filler in said recess, and a fillet of adhesivebinding together said members and said filler.

12. A loud speaker comprising a diaphragm, a member located at the back of the diaphragm having a periphery corresponding in shape with that of the diaphragm, said diaphragm and member being joined near their edges and having outwardly flaring peripheral portions forming a recess between them, and a filler located in said recess concealing the joint between the diaphragm and said member.

13. A loud speaker comprising a diaphragm, a member located at the back of the diaphragm having a periphery corresponding in shape with that of the diaphragm, said diaphragm and member having outwardly flaring peripheral portions forming a recess between them, a filler located in said recess and a body of adhesive bindin to ether the diaphragm, said member and t e Her.

14. A loud speaker comprising a diaphragm, amember located at the back of the diaphragm having a periphery corresponding in shape with that of the diaphragm, and a cord cemented in place between the peripheral edge portions of the diaphragm and said member.

In testimony whereof we afiix our signatures.

CLAIR L. FARRAND. PAUL F. GODLEYQ ERNEST ROSS. 

